Hallux Rigidus

Original Editor - Tracy Hall

Top Contributors - Admin, Ewa Jaraczewska, Rachael Lowe, Jess Bell, Tracy Hall, Laura Ritchie, Kim Jackson, Ilse De Bode, Simisola Ajeyalemi and Khloud Shreif  

Introduction

Hallux Rigidus is an osteoarthritic degenerative condition of the 1st metatarsophalangeal joint (MPJ-1) characterised by a complete absence of the joint's sagittal plane motion, specifically dorsiflexion at the end stage of the disease. Hallux Limitus (HL) is the earlier stage of this condition with restriction in the sagittal plane of motion. This article will discuss multiple conservative management concepts and main operative procedures in treating hallux rigidus.

Clinically Relevant Anatomy

Structure

The first metatarsophalangeal joint consists of several anatomic structures which, during athletic activities, must support a weight up to eight times heavier than the body.

Osseous components:

• First metatarsal head with two grooves on its plantar surface accommodates the articular surfaces of the medial and lateral sesamoid bones. The dorsal aspect of the first metatarsal head is the location of the cartilage lesions.
• Proximal phalanx serves as muscular and ligamentous attachments
• The medial (tibial) and lateral (fibular) sesamoid bones are located on the plantar surface of the first metatarsal head.

Plantar plate complex of the great toe:

This fibrocartilaginous pad forms a functional unit with a plantar capsule, intersesamoid ligament, paired metatarsosesamoid ligaments, sesamoid phalangeal ligaments, and musculotendinous structures of the first MPJ. Its role includes dispersing body weight to the sesamoids, protecting the articular surfaces, allowing gliding of the metatarsal head along the joint capsule and at the smaller sesamoid articulations, assisting propulsion during gait and sports activities, allowing effective acceleration and maintaining optimal body balance.

Collateral ligaments:

Medial and lateral metatarsophalangeal ligaments (collateral ligaments) originate from the metatarsal condyle tubercle and insert into the tubercle at the base of the proximal phalanx. Despite not belonging to the plantar plate complex, they provide a static stabilisation during valgus or varus forces applied to the joint.

Dorsal extensor tendons:

Extensor hallucis longus (EHL) and extensor hallucis brevis (EHB) tendons provide dynamic stability during plantar flexion.

Sagittal bands:

These ligaments encircle the metatarsophalangeal joint. They are adjacent to the joint capsule and extend from the tendons to the sesamoids. They stabilise and centralise the extensor tendons during motion.

Function

• In the normal resting position, the 1st metatarsophalangeal joint relative to the longitudinal axis of the 1st metatarsal is positioned with 16 degrees of dorsiflexion.

• Range of motion: passive plantarflexion is 3-43 degrees, and passive dorsiflexion is between 40 and 100 degrees
• Nawoczenski et al. showed a new standard of “normal” range of dorsiflexion range of motion of the great toe joint should now be set at approximately 45 degrees. However, this dorsiflexion range has only been verified for walking gait, not running.

• A normal gait cycle requires 45-60 degrees of 1st metatarsophalangeal extension.
  

Function of the Hallux

The hallux is critical for normal functioning and activity:

1. During the normal stance phase of the gait cycle, the hallux bears twice the load compared with the other toes and approximately 40-60% of the body weight.
2. During the dynamic activity, the great toe aids in the foot's natural movement, allowing the body to move forward in space. Read about Windlass mechanism here.
3. The great toe plays an important role in the ability to have static and dynamic balance. The single-leg stance performance and the directional control ability during forward/backward weight shifting can be impaired due to the great toe constraints.

Aetiology

The majority of hallux rigidus cases are idiopathic. Traumatic or iatrogenic injuries can directly cause damage to the articular cartilage of the MTP joint and lead to the development of HR. Additionally, the presence of structural changes may correlate with the development of HR and HL:

• Coughlin and Shurnas reported an association of hallux rigidus with flat or chevron-shaped metatarsophalangeal joint, metatarsus adductus, and hallux valgus interphalangeus.
• Dorsiflexed first metatarsal relative to the second metatarsal
• Plantar flexed forefoot on the rear foot
• Reduced first metatarsophalangeal joint range of motion
• Longer proximal phalanx, distal phalanx, medial sesamoid, and lateral sesamoid
• Wider first metatarsal and proximal phalanx

Risk Factors

• According to a study conducted by Senga et al., knee osteoarthritis, hallux valgus and gout attack were independent risk factors for HR
• Bilateral involvement in patients with a family history of HR
• Unilateral involvement in patients with a history of trauma
• Higher HR prevalence in elderly (≥50 years)
• Female sex correlates with greater frequency of hallux rigidus
• The patient's height relates to a greater frequency of hallux rigidus: "the greater the height of the patient, the greater the development of hallux rigidus".

Clinical Presentation

Hallux Rigidus presents with various signs and symptoms, including:

• Pain (Burning pain and paraesthesia might be present)
• Swelling and redness of the joint
• Stiffness
• Loss of motion (A total absence of movement)
• Reduced ankle joint plantarflexion
• Plantar calluses
• Joint enlargement

The following functional limitations can be present:

• Increased pain with walking, running, or squatting
• Antalgic gait pattern:
  • Decreased toe-off
  • Shortened stride or step length
  • Compensatory adaptations including:
    • External rotation of the ipsilateral hip,
    • Hip hiking and circumduction to allow the toe of the involved limb to clear the floor during the swing phase of gait.

• Increase in lateral forefoot loading (uneven shoe wear with evidence of increased wear under the MPJ-2 and lateral forefoot)
• Less total ankle joint excursion during level walking
• An increased forefoot supination during push-off

Diagnostic Procedures

Radiograph

Weight-bearing, anterior-posterior and lateral radiographs are usually needed to examine the joint. Often, non-uniform joint space narrowing, widening or flattening of the 1st MT head is seen. Subchondral sclerosis or cysts, horseshoe-shaped osteophytes, lateral greater than medial osteophytes and sesamoid hypertrophy may be seen.

Classification Systems for Hallux Rigidus

Regnauld Classification

A clinical/radiographic grading system described by Regnauld appears mainly in the European literature:

• Grade I: functional hallux limitus
• Grade II: joint adaptation with flattening of the first metatarsal head and pain at the end range of motion
• Grade III arthrosis with severe flattening of the first metatarsal head, osteophytes, asymmetric joint space narrowing, and erosions

Hattrup and Johnson Classification

• Grade I: mild to the moderate formation of osteophytes with no joint space involvement
• Grade II: moderate osteophyte formation, joint space narrowing and subchondral sclerosis
• Grade III: increased osteophyte formation and loss of joint space

Coughlin and Shurnass Classification

Coughlin et al modified the Hattrup and Johnson classification to create the Coughlin and Shurnass classification:

• Grade 0: Dorsiflexion 40-60°, normal radiography, pain not present
• Grade 1: Dorsiflexion 30-40°, dorsal osteophytes, minimal/ no other joint changes
• Grade 2:Dorsiflexion 10-30°, mild to moderate joint narrowing or sclerosis, osteophytes
• Grade 3: Dorsiflexion less than 10°, severe radiographic changes, constant moderate to severe pain at extremities
• Grade 4: Stiff joint, severe changes with loose bodies and osteochondritis dissecans

Roukis Classification

• Grade 1: Metatarsus primus elevates, periarticular subchondral sclerosis, minimal dorsal exostosis and minimal flattening of the metatarsal head
• Grade 2: Moderate dorsal exostosis, flattening metatarsal head, minimal joint space narrowing, sesamoid hypertrophy
• Grade 3: Severe dorsal exostosis, focal joint space narrowing, cyst formation, loose bodies
• Grade 4: Excessive exostosis of the metatarsal head and proximal phalanx base, absent joint space, ankylosis

Examination

Physical examination of the patient with hallux rigidus should include the following:

• Observation: osteophytes can be visualised and palpated, and foot shape and the alignment of the great toe can be altered.
• Palpation: tenderness can be present at the dorsal joint. Extreme dorsiflexion may produce pain due to an impingement of the dorsal osteophytes. Additionally, the extensor hallucis longus (EHL) traction over the dorsal osteophytes during plantar flexion can cause pain.
• First MTP joint compression: positive "grind testing" indicate more advanced arthritis. Pain with compression of the first MTP joint, also known as ‘grind testing’, and pain during the middle of the range of motion may indicate more advanced arthritis. Patients may also demonstrate hyperextension of the first interphalangeal (IP) joint as a reaction to limited first MTP dorsiflexion.
• Range of motion assessment: ankle dorsiflexion and plantar flexion range of motion. In advanced arthritis, the patient reports pain during the middle of the range of motion. The degree of rigidity can be defined by the pain provoked by dorsiflexion, plantarflexion or throughout the range of movement.
  

1st MTP joint extension test:

• Passive testing: Patient in standing position, knee flexed: passively lift the big toe. Next, manually laterally rotate the tibia through the calf muscles. It allows the subtalar joint to supinate and increase the height of the medial longitudinal arch. Again passively lift up the big toe. The difference between the two measures may be because tension on the plantar fascia is decreased, allowing the big toe to extend further.
• Active testing: Patient in standing position. Stabilise the phalange on the ground and bring the same knee into flexion and ankle into plantarflexion, which results in the extension of the MTP joint.
  

Non-Surgical Management

Pharmacology

• Treatment for mild or moderate cases of Hallux rigidus includes anti-inflammatory NSAIDS medications that are often prescribed and usually start to relieve some symptoms.

• Cortisone injections give relief within 24 hours but often are only temporary (three months).
• Intra-articular injection of sodium hyaluronate resulted in a "decrease in pain and improvement of function at three months after the injection"

Footwear, Insoles and Orthotics

Goal: to block or shield the hallux from dorsiflexion at the first metatarsal.

The following footwear modifications are a grade C recommendations:

• Molded stiff inserts with a rigid bar or rocker bottom shoes. Rocker-bottom soles may be appropriate to off-load the extension moment of the MPJ-1 during toe-off.
• Stiff sole footwear or graphite inserts can help to decrease the extension moment at the MPJ-1
• Shoes with a large toe box and cessation of high heels

Manual Techniques

Goal:

1. To keep the talocrural joint mobile in order to preserve function
2. To decrease pain with compression
3. To preserve and increase MPJ-1 plantarflexion and dorsiflexion

The following techniques are recommended (Grade C evidence)

• 1st MTP distraction either alone or with dorsal and plantar glides
• Grade III joint mobilisations on the medial and lateral sesamoids of the affected first MPJ

Strengthening

Goal: to improve stability of the 1st MTP

• Isometric contractions of the flexor hallucis longus muscles with 10 seconds hold
• Isotonic strengthening of the flexor hallucis longus with manual resistance
• Strengthening of the plantar intrinsics muscles

Activity Modification

Runners with stage II and greater hallux rigidus may need to switch to lightweight day hikers and switch from asphalt to dirt trails for long distance running.

Surgical therapy

The indication for surgery is intractable pain isolated to the first metatarsophalangeal joint that is refractory to shoe modification, use of rigid shoe inserts, nonsteroidal anti-inflammatory medications, and modification of activities. Choice depends on the stage of involvement, the limitations in range of motion, the activity level of the patient and the preferences of the surgeon and patient.

Types of surgery include:

• Cheilectomy. Treatment of choice for early stages of hallux rigidus that includes a resection of < 30% of the dorsal metatarsal head and removal of bone spurs at the top of the joint. Usually beneficial for mild to moderate disease with less than 50% of joint affected usually grade 1 and grade 2 .

• Dorsiflexion phalangeal osteotomy (Moberg osteotomy). In patients with a reasonable range of motion, a dorsal wedge osteotomy of the phalanx increases dorsiflexion at a theoretical cost of loss of plantar flexion. It is typically performed in conjunction with a cheilectomy. Mild to moderate cases occasionally require this procedure.

• Excision Arthroplasty or Keller procedure.  The Keller procedure is when resection of the base of the proximal phalanx and soft-tissue reconstruction is performed with the intention to decompress the joint and improve pain and range of movement. The Keller procedure may lead to great toe weakness, cock-up deformity and metatarsalgia.

• MTP Arthrodesis. This is a procedure is performed to fuse the joint surfaces. It is a gold standard surgery for end stage hallux rigidus, and is recommended when other procedures have failed (for example Keller procedure). Arthrodesis of the first MPJ consistently show superior results and patient satisfaction in comparison to other surgical options. While cheilectomy may be beneficial for early stages of hallux rigidus, arthrodesis of the first MPJ appears to be the best option for the relief of symptoms with stage III and stage IV hallux rigidus in active, athletic patients.

• Artificial joint replacement. A procedure to replace joint surfaces with a plastic or metal surface. This technique of soft-tissue interposition arthroplasty gave excellent pain relief and reliable function of the hallux, and is an alternative treatment to MTP arthrodesis in select cases of severe hallux rigidus.  The downside to this is the joint may not last a life time and there is currently no study documenting the long-term performance of any first MTP joint prosthesis in running athletes.

Differential Diagnosis

Turf toe, fracture, gout, rheumatoid arthritis could be some other causes of pain and stiffness in the 1st MTP joint.

Resources

Richie D. How To Treat Hallux Rigidus In Runners. 4 April 2009. Available from: www.podiatrytoday.com/how-to-treat-hallux-rigidus-in-runners. [last accessed 5/6/9]

Foot and Ankle Center of Washington, Seattle. Available at www.footankle.com/Hallux-Rigidus.htm [last accessed 24/5/9].